Serum lipid and lipoprotein studies will be conducted on mice with free cholesterol storage disease and compared to non-affected colony mice from free cholesterol storage disease carriers and out of colony control animals. Selected tissues will be studied for their cholesterol and lipid content and pathologic involvement in the same groups of animals. The distribution of the phospholipids in tissues will be studied and the fatty acid profile of selected tissues will be analyzed. Tissue sterols of some tissues will be separated by multiple thin layer chromatography and evaluated for non-cholesterol sterol content by mass spectrometer-gas liquid chromatography. Fractionation of liver sub cellular organelles by isopycnic ultracentrifugation will be carried out. The cholesterol and protein content, organelle enzyme activity patterns, and electron microscopic evaluation for purity will be conducted on the purified fractions. In particular, latency and median density of the fractions will be carefully monitored.